Antenna selector switch



May 22, 1945. ug-rm 2,376,649

ANTENNA SELECTOR SWITCH Filed March 28, 1944 RECEIVER RECEIVER Inventor Kirby 13. Austin,

H is Attorney.

Patented May 22, 1945 ANTENNA SELECTOR swrron Kirby B. Austin, Bridgeport, Conn, assignor to General Electric Company, a corporation of New York Application March 28, 1944, Serial No. 528,484

4 Claims.

My invention relates to a switching scheme for use' in connection'with radio receivers adapted to be connected alternatively to antennae of different types.

Where an antenna of the ordinary vertical, or capacitive, type is to be used alternatively with different receivers, one of which may also employ a loop alternatively to said capacitive antenna, special means may be required to prevent undesired capacitive coupling between the capacitive antenna and the input to the receiver when the loop is in use. An object of my invention is to provide such means in an entirely practical and feasible form whereby the capacitive antenna and loop may both be used simultaneously with different receivers without objectionable capacitive coupling therebetween.

Another object of my invention is to provide a simple and economical switching structure capable providing the required switching operations having. incorporated therewith shielding and grounding means to avoid the undesired capacitive coupling.

The novel features which I believe to be characteristic of my invention areset forth with particularity in the appended claims. tion itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in .connection with the accompanying drawing in which Fig. 1 represents schematically my invention and Fig. 2 represents a physical embodiment of the relay employed.

Referring to Fig. 1, I have shown therein two double-throw switches, one comprising a stationary contact I, a movable contact 2 and a stationary contact 3 and the other comprising a stationary contact 4, a movable contact 5 and a stationary contact 6. The two movable contacts 2 and 5 are arranged to be reciprocated between the cooperating stationary contacts in accord with the operation of a switch I which controls the energization of a magnet 8 to reciprocate the movable contacts 2 and 5. The magnet 8 may be energized from a battery 9 when the switch I is closed.

The switches I, 2, 3 and 4, 5, 6 are arranged alternatively to connect a capacitive antenna l2 and a loop antenna l3 to-a radio receiver l4'and to prevent any coupling from the antenna l2 to the input of receiver l4'when the loop antenna 13 is in use. Thus the antenna l2 may be employed to supply signals to a second receiver [5 My inven-' through a switch Hi When the loop antenna I3 is in use with the receiver l4.

To effect these switching operations the contact 3 is grounded. The movable contact 2 is connected through a conductor H to the stationary contact 4 of the other switch. The p I3 is connected between ground and the stationary contact E, and the movable contact 5 is connected through conductor i8 to the input of the receiver 14. Thus when switch I is closed and contacts 2 and 5 are in the position shown in the drawing, the loop antenna 13 is disconnected from receiver l4 and the antenna I2 is connected thereto through contacts I and 2 of one switch, conductor ll, contacts 4 and 5 of the other switch, and conductor l8. When switch I is open and coil 8 is deenergized, contacts 2 and 5 disengage contacts I and 4 respectively and engage contacts 3 and 6. The high voltage side of the loop I3 is then connected to the receiver through contacts 6 and 5 and conductor [8, the low voltage side'thereof being grounded, that is, of course, the opposite terminal of the input circuit of the receiver 14. The movable contact 2, which is adjacent the contact I connected to the antenna 12, is now grounded being in engagement with contact 3. This also operates through conductor 11 to ground contact 4 of the other switch. Thus capacitive coupling from the contact I to the input of the receiver 14 is reduced due to the grounding of its adjacent contact 2 and the contact 4.

This capacitive coupling is further reduced by a shield member l9 interposed between the two switches in a manner the details of which clearly appear from Fig. 2.

The physical structure of the switch mechanism described in connection with Fig. 1 is illustrated in Fig. 2 where the magnet 8 is shown having a magnetizable armature 22 carrying a nonconducting piece 23 upon which metallic contact members 24 and 25 are mounted. This armature 22 and these metallic contact members are reciprocated by the energization and deenergization of coil 8. Movable contact 5 is carried at the upper end of member 25, and contact 2, not shown in Fig. 2 is carried at the upper end of member 24. Contact 5 reciprocates between stationary contact 6 mounted upon terminal member 32 carried by a block of insulating material 28 supported above the coil 8 and the further contact 4 carried by terminal member 33 also mounted upon the block 28. The upper end of member 24 reciprocates between similar contacts only one of Which, 3, appears in Fig. 2,

these contacts being carried by member 2"! and 29 similarly mounted upon the insulation block 28. Conducting member 24 is connected through conductor I! to a terminal member mounted on the block 28, which may be connected to contact member 33 carried at the opposite side of the member 28 and which in turn supports the contact 4 as shown in Fig. 1. The conducting armature member 25- is also connected by a conductor l8 to a terminal member 36 carried on the block 28 to which the receiver may be connected.

The loop antenna 13 is of course connected between terminal members 32 and ground. Terminal 32 carries contact 6 and terminal 21 carrying contact 3 is grounded in any suitable way.

Two further terminal members 42 and 43 are shown mounted upon the block 28. These members may be connected to the terminals of the magnetizing coil 8 and to any suitable circuit for .controlling the energization of that winding.

This circuit may be extended to the switch I, which may be located at a remote point;

The shield l9 mentioned in connection with Fig. 1 is shown in Fig. 2 mounted upon the block 28 to shield the various portions of the two double-throw switches apart. This shield member comprises a vertical conducting plate which is attached to the member 28 by means of a conducting screw 44, which extends into the metallic conducting frame member 45 which may be grounded. This shield plate l9 also has a hookshaped portion 46 extending beyond and below the right-hand end of the block 28 more completely to shield the two double-throw switches from each other.

A further shield 48 extending about two sides of the relay is shown in Fig. 2 electrically to isclate the relay structure from other portions of the equipment in which it may be incorporated, as for example, from the movable portions of the unicontrolled variable condenser, which ma be employed where the relay is incorporated in the radio receiver. This member 48 is of course connected to the frame member 45 and grounded.

While I have illustrated a particular embodiment of my invention, it will of course be understood that I do not wish to be limited thereto since various modifications both in the circuit arrangement and in the instrumentalities employed may be made, and I contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim a new and desire to secure by Letters Patent of the United States is:

1. In combination, a capacitive antenna, a loop antenna, two double-throw switches each having a movable contact and oppositely disposed stationary contacts, means to operate said movable contacts in unison into alternative engagement with said stationary contacts, one of Said stationary contacts being grounded and said loop antenna being connected between ground and the corresponding stationary contact of the other switch, the movable contact cooperating with said grounded contact being connected to the opposite stationary contact of the other switch, and

having its opposite cooperating contact connected to said capacitive antenna, and a receiver connected to the other of said movable contacts.

2. In combination, a capacitive antenna, a loop antenna, two double-throw switches, each havinga movable contact and oppositely disposed stationary contacts, means to operate said movable contacts in unison into alternative engagement with said stationary contacts, said loop antenna being connected between respective stationary contacts of said two switches which are engaged simultaneously by said movable contacts, one of said movable contacts being connected to the opposite stationary contact of the other switch and having its opposite cooperating stationary contact connected to said capacitive antenna, and a receiver connected to the other movable contact.

3. In combination, a capacitive antenna, a loop antenna, two double-throw switches, each having a movable contact and oppositely disposed stationary contacts, means to operate said movable contacts in unison into alternative engagement with said stationary contacts, said loop antenna being connected between respective stationary contacts of said two switches which are engaged simultaneously by said movable contacts, one of said respective stationary contacts being grounded and the movalble contact cooperating therewith being connected to the opposite stationary contact of the other switch, the opposite stationary contact cooperating with said last mentioned movable contact being connected to said capacitive antenna, and a receiver connected to the other movable contact, whereby when said loop antenna is connected to said receiver the movable contact cooperating with the contact to which said capacitive antenna is connected and the corresponding stationary contact of the other switch are both grounded.

4. In combination, a capacitive antenna, a loop antenna, two double-throw switches, each having a movable contact and oppositely disposed stationary contacts, means to operate said movable contacts in unison into alternative engagement with said stationary contacts, said loop antenna being connected between respective stationary contacts of'said two switches which are engaged simultaneously by said movable contacts, one of said respective stationary contacts being grounded and the movable contact cooperating therewith being connected to the opposite stationary contact of the other switch, the opposite stationary contact cooperating with said last mentioned movable contact being connected to said capacitive antenna, a receiver connected to the other movable contact, whereby when said loop antenna is connected to said receiver the movable contact cooperating with the contact to which said capacitive antenna is connected is grounded, and a shield interposed between said switches to shield contacts connected to said capacitive antenna from contacts connected to said receiver when said loop is connected to said receiver.

KIRBY B. AUSTIN. 

